Re: Gtk version getting closer

[Richard Stallman]

    You first select "What's this?" if it's available (not always provided
    and sometimes it's a simple "?" next to the window's minimize button).
    Then you select the "leaf" menu item of interest (ie. menus with
    submenus don't trigger the "What's this?").  The menu remains open
    during and after the tooltip is shown.

This is almost identical to C-h k.  That shows the doc string of the
menu item command.

It is good to make sure each menu item has a function name and a doc
string--to avoid anonymous lambdas there.  I made some changes
of that sort a few months ago, and I think I got rid of them all.